(CNN) Boeing says it has finished the development of a software fix to its troubled 737 Max, in a statement released Thursday. The plane maker says it has flown the aircraft with the updated software on 207 flights for more than 360 hours. This is the next step in what Boeing hopes will result in the Federal Aviation Administration allowing the plane to resume commercial service. (www.cnn.com) Plus d'info...

According to what I have read from credible sources (including credible reports of Boeing internal documentation and various American, US based, pilots), I understand the following to be facts.

Boeing were aware there was a defect in their MCAS software, fed only from the port AOA sensor, in November 2017. Lion Air crashed in October 2018. The port AOA sensor appeared involved with the Lion Air crash.

In November 2018 Boeing promised updated MCAS software within a few weeks.

In March 2019 Ehiopian Airlines crashed. Documentation submitted by Boeing to the FAA and others stated that the maximum trim deflection of the horizontal stabilizer was 0.6 degrees. The deflection on the crashed Ethiopian stabilizer was 2.4 degrees. Boeing admitted that they had changed the MCAS program without informing any external entities.

The Max was grounded by everyone, including Canada, except the FAA and Costa Rica. The FAA then decided to ground the Max.

In May 2019, eighteen months after Boeing were aware there was a defect in their MCAS software, and six months after American and Southwest US based pilots were complaining about it, Boeing finally thinks it might have resolved this defect.

If my understanding is incorrect, can someone please tell me what I have misunderstood.

If my understanding is substantially correct what was Boeing doing between November 2017 and March 2019 when they were forced to address the issue ? And how much other software has Boeing had specifically created and tested for the Max and are Boeing aware of any "defects" in this other software ?

Frank, you pretty much have the problem well defined. I would add that pilots were not made aware of the MCAS until problems were reported, and then were not told of software updates to the MCAS that evidently made the problem worse. Without knowing the MCAS was there, and later that the "fix" did not resolve anything, I think at some point there needs to be a way for pilots to disable the MCAS entirely in order to better regain and/or maintain proper control of the aircraft in the event of future problems with the system.

It should be noted that the MCAS is intended to operate autonomously to pilot input when the aircraft is NOT on autopilot, such as during initial departure and on final. This I find odd, should not the pilot have full command of the aircraft when not using autopilot? And why is there no option to the pilot to disable the system, particularly when it is malfunctioning?

Also, with this aircraft being significantly different in design and flight characteristics, why is Boeing claiming no training required, and carriers assuming Boeing is right? I can only assume this was a selling point, since no training translates to carrier savings, at the expense of aircrews and passengers.

The 737 MAX is a stable and safe aircraft in its original design. Unfortunately in a few flight envelopes it did not perform exactly like other 737's, so Boeing designed MCAS, so that it would. Without MCAS, the MAX would require separate certifiction for pilots to fly it, which would have added significant training costs. Right now a pilot is certified to fly a 737, regardless of which series it is (300 to 900). From Boeings standpoint, the MAX could NOT have different flying characteristics, otherwise it may as well not be called a 737. The problem isn't the plane, its MCAS.

You sort of hit the nail on the head with part of your statement "Without MCAS, the MAX would require separate certifiction for pilots to fly it, which would have added significant training costs" Not Just training costs but other costs as well, and Boeing was eager to stay ahead of Airbus's A300 NEO family.The funny thing is...the MAX really isn't that stable on takeoff...it wants to nose up more than appreciated. THAT is the main reason the flawed MCAS system was initialized..and yes I said flawed as in it should have relied on readings from 2 or more sensors AT the beginning!

And yet A320 NEO flies without MCAS and meets the customers efficiency needs. If Boeing had spent a lot more money on the plane design to fix the thrust vectoring problems of the oversize engines mounted in a poorly researched position, special certification wouldn't have been needed nor MCAS.Now it's costing way more cash than a physical design fix.

For some nagging reason I just cannot count on the word of Boeing. They lied their way with the LION crash. The ETHIOPIAN crash just sank BOEING. A year of lies and coverups.This manufacturer to this date had an imppecable safety record. However when you lie to your best clients for more than a year your credibility is very low. BOEING must replace all of those in the senior executive positions.

Real easy you are a troll nothing else know little about things it seems. Dumb ass pilots in one did not retard the power kept it full on right up till it hit the GROUND. Could things have been done different? YES when speed is increasing full power should not be KEPT on Killing Any chance of recovery. Now take a pill find another place to post your stupid comment. OK?

And it seems your knowledge base is even less..Dumb ass poster!! Maybe use that grey matter to research and follow along...full fledged North American 737 pilots used a MAX simulator and stated "There was nothing the Ethiopian crew could have done to get out of the situation" STOP TRYING TO PROTECT AN ENTITY WHO WAS TOLD OF FLAWS BEFORE THE DANG JET WAS EVEN RELEASED!!

A different take. With the 787, Boeing outsourced key aircraft components and took the approach that the supply chain would supply the components. Boeing would literally just snap them together like a model airplane. My take is this - is it possible non-aviation decisionmakers are making critical aviation decisions? It's just hard to believe that aviation engineers and managers would look at the MCAS and believe it doesn't require additional training. At what level is this kind of decision made?

Day by day it becomes clear that the Boeing board has some serious work ahead replacing anyone involved with managing the MAX series of aircraft, from the CEO and down the lines of financial, procurement, and engineering management.

It does not matter if they were around 103 yrs..if they knew what they were doing, in this instance, the MAX would not be grounded! And yes, even they admit they messed up.BTW..in the future, might want to curb the tongue just a bit.

Complacency kills. Think of it this way. At some point a group if high kevel executives got together in a room (or on a teleconference) and said "We have to add a program to make the MAX fly like other 737's, it will manipulate the control surfaces without pilot input, and we don;t need to tell the airlines, pilots, or FAA that we are doing this"...and the rest of the group said "okay, that sounds good". Perhaps moving to CHicago has removed them too far from the plane building environment. Boeing should be better than that, and should absolutely be better than saying "that's the way we've always done it" as an excuse.

For some nagging reason I cannot figure out why the pilots of one crash kept full power on right up to the time it hit the ground. Now about dumb pilots with low time, poor training...…………..where does that come into the picture? Seems in another AC with the same problem a third pilot flipped the switches and took care of it. Crew training?

Not just that but has "it" ever piloted an aircraft that should never have been sold to those airlines...and this is from Boeing's own mouth "“cannot be used at what are referred to as ‘high/hot’ airports." Boeing knows the regions the aircraft operate in so question is "Why did Boeing sell an aircaft it knew could not be properly used in the regions?" Both crashes occurred in those regions so maybe dumba$$ linbb can comment on that

I agree. Boeing is foolish to believe saying all the plane needed was a software update. But linbb can freely talk ill of the dead because they are not here to defend themselves. Plus linbb was never in their shoes under the circumstances they were given. Linbb has all hindsight regarding this matter so to call these pilots out their name truly shows what type of character linbb is.. "troll".

But back to Boeing. If this software update is all they need to remedy this crisis, and the FAA is ok with just that, then the future of Boeing has been undermined because going forward this is not worthy of historic Boeing we all know and loved, nor the corporations they assimilated, McDonnell Douglas, etc. And airlines like Southwest will be doomed if rather they had an all max fleet, they would have completely been wiped out. Just consider Delta's current position, has had no max planes in fleet and is uneffected by this grounding.

LIKE !!! The Liar in Chief - and also the spoiled rich kid, who thinks that he actually did something great. When in fact.. had he never touched a thing that his father left him, he'd be worth ten times what he thinks he is.